SAT prep help
posted by Anonymous on .
Set M consists of the consecutive integers from 15 to y, inclusive. If the sum of all the integers in set M is 70, How many numbers are in the set?

a. 33
b. 34
c. 35
d. 36
e. 37 
15 to +15 includes 31 integers, counting zero. The sum is zero.
so 16+17+18+19=70 (ie, 17.5 x 4).
so I count 31+5 integers.